net/mlx5: fix flow split combined with age action

net/mlx5: fix flow split combined with age action

Currently, for a flow containing an age action, if flow is split to
sub-flows, a new age action will be created for each sub-flow.
However only the action created for the last sub-flow will be queried
on flow query and cleared on flow removal.

This behavior is wrong, causing a leak of resources.
Need to create just one action per flow, and use it for all sub-flows.

This patch adds the required check to make sure an age action is
created just once per flow, and used by all sub-flows.

Fixes: f935ed4b645a ("net/mlx5: support flow hit action for aging")
Cc: stable@dpdk.org
Signed-off-by: Dekel Peled <dekelp@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>